Method of making watch-springs



-(No Model.)

' J. LOGAN.

METHOD 0? MAKING .WATGH SPRINGS.

110,377,489. PatentedFe b. 7, 1883.1

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W/TNEEEE EQ I W E- i UNITED STATES Pnf jizntr ,QFEICE loo nit LOGAN, or WALTHAM, MnssAonosn'r rs.

Ma l-Honor MAKING wA'rol-l-spnmes.

SPECIFICATION forming part of Iretterl Patent No. 877,489, dated gebruary I, 1888.

Q Application died September 30, 1887. Serial No.9.'l1.090. (No model.)

coiled as shown in Fig. 2, after the tempering operation, the springbeing released. Fig. represents the springas coiled the second time. Fig. 6 represents the completed spring released. Figs. 2, 3, 4, and 5 show the spring considerably enlarged. I

The same letters of reference indicate the same parts in all the figures.

In carrying out my invention make the '60 spring in. the ordinary form of a straight ribbon, a, Fig. 1, and "after determining the length of spring to be used I punch-in each end of it an eye, b, of the same form as that ordinarily punched in the'inner end only, each eye being formed to engage a stud or pin on an arbor. Then, the temper having previously been drawn sufiiciently low.to allow of safely coiling the spring ona large arbor, 0, say three or four times the size of the barrelarbor, one end of the ribbon is engaged by the ye therein with the largerarbor, and the rib- .bon is tightly coiled thereon, as shown in Fig. 2. Then while the ribbon is so coiled it is transferred to a circular cup or capsule, d, (shown in Fig. 3,) and then is submitted to the action of a sufficient degree of heat to produce a safe spring-temper. When cool, the spring t is removed from the cup, when it will be found set-in the form of a helical or flat spiral. (Shown in Fig. 4.) I then coil the spring on an ordinary arbor or winder, f, but in a re verse direction, as shown in Fig. '5, and commencing with the other end of the spring, so-

To all whom it may concern:

Be it known that I, Jonn Loom, of Walthem, in the c'ounty.of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Mainsprings for Watches, 800., and the Method of Making the Same, of which the following is a specification. The motive power of a watch is stored up in the mainspring, which may be described as a narrow ribbon of tempered steel which is coiled up inthe barrel. When the spring is wound up-i. e., coiled closely upon itself around the barrel-arbor, to which the inner end of the spring is attachedr-the effort of the, spring is to uncoil itself or straighten out; but as the arbor, to which the innerend of the spring is ordinarily fastened, is prevented from turning, the spring of course reacts upon the inclosing-barre], to which its outer end is attached, and causes it to turn as fast as the action of the train'will allow. In an ordinary pocket-watch the room which can be given to the barrel and its inclosed mainspring is of necessity quite limited, and therefore the great desideratum is toget a spring as thin as possible, that there may be length sufl'icient to give the requisite number of turns to thebarrel to run the watch certainly not" less thantweflty-four hours, and preferably thirty-six to forty hours. If, however, the spring be made too thin, the result will be that its action will be so weak as to fail to impart a proper motion to the balance, which will be unsteady in action and easily stopped.

The object of my invention. is to provide a the spring which was hooked to the windingspring which may be made thinner than the arbor at the first winding willbe the outer end ordinary spring, and-at the' same time be so and will have a backward or reverse curve, formed as to possess the life or pull which and the entire spring will open to a much that when coiled thesecond time the end of will enable it to drive the train the desired 0 length-of time without sensible loss of power. My invention therefore consists in the improved spring and the method of making the same, hereinafter described and claimed. 0f the accompanying drawings, forming a 5 part of this specification,

a view of the ribbon of which my improved spring is made. Fig. 2 the spring as coiled on the larger arbor or winder. Fig. 3 represents a view of the spring, 50 coiled as shown in Fig. 2, transferred to a holder or capsule. Fig.4repres'ents thespring,

Figure 1 represents represents a view of greater eitent than a spring coiled in the ordinary manner, ability of a spring to open is the measure of "its power or efiectivenesss, it is evident that springs made in this manner will possess a greater power and consequent value than those coiled ,in the ordinary manner.

j Having thus described myimproved method,

I desireto claim-.

- 11. The improved method hereinbefore .de-f

scribed of making mainsprings, the same consisting in coiling the steel ribbon from which the spring is to be made on an arbor of greater as shown in Fig. 6. As the diameter than the barrel-arbor to which the completed spring is to be applied, then tempering it while it is so coiled, and finally coiling the spring in a reverse direction on a 5 smaller arbor, as set forth.

2. The improved method hereinbefore described of making mainsprings, the same consisting in first partially drawing the temper of the steel ribbon from which the spring is to be 10 made, then coiling the same on an arbor of greater diameter than the barrel-arbor to which the completed spring is to be applied, then tempering it while it is so coilwl, and finally coiling the spring in a reverse direction on a smaller arbor, as set lbrth. 15 In testimony whereof I have signed my name to this specification, in the presence of two s'nbscribing witn this 28th day of September,

JOHN LOGAN. 

